The Trusted Computing Group (TCG) has specified the concept of a memory override (MOR) bit. If the MOR bit is set, a Basic Input/Output System (BIOS) performs a memory scrub during a boot process to ensure secrets stored in system memory are deleted prior to being exposed.
Although the MOR bit can be used to prevent attacks (e.g., reset or power cycle attacks) from being effective, some existing implementations lack sophistication. For example, some computer systems maintain the MOR bit in a set condition, which causes the BIOS to unnecessarily perform a memory scrub during each boot process. Also, each memory scrub causes a delay in the boot process, which may cause a user to believe the computer system is “hung.”